The Business & Social Network
Casinos make money when you gamble. Everything else is there to make your gaming experience more fun; free food, free drinks, free entry, couple of chips to get your started, maybe even free accommodation. It's about keeping punters at tables.
The last thing a casino wants is for you to leave because you're hungry. Or worse still, leaving the premises to try that new restaurant down the block. If that happens, they know they've lost you for the night. So they give you free food. It doesn't even have to be very good, just free. Who can turn down free food!
This same approach can be applied to virtual worlds.